Pressure treated lumber nails anchor - down shank ptl - stormguard 5# box size=12d length 3-1/4 inch For pressure treated cedar lumber and redwood. Double hot dipped zinc coated. Made from a stiffer stock steel. These nails are made from stiffer stock steel so the shanks can be smaller in diameter to help reduce wood splitting without bending. Ring shanks provide exceptional holding power. Producers of treated lumber and many building codes specify hot-dip galvanized or stainless steel nails because they have a rust-free life expectancy comparable to that of the treated lumber. Nails are double dipped in molten zinc. For pressure treated cedar lumber and redwood. Double hot dipped zinc coated. Made from a stiffer stock steel.